Recently, plenty of wood-cement boards are used as a siding board of a house. Said wood-cement board is manufactured by the dry or semi-dry method wherein a raw material mixture including cement material and wood flake is strewed on a mold panel to form a mat and said mat is cured by pressing with moisture.
By applying the dry or semi-dry method to manufacture the wood-cement board, a clear-cut design can be easily given on the surface of the wood-cement board so that the dry or semi-dry method may be useful to manufacture the siding board having a clear-cut design like natural stones or tiles on its surface.
Nevertheless, in a case where said wood-cement board is used as a siding board, said wood-cement board may be exposed to the outside environment such as wind, rain, and the like and when the curing of the cement material in said wood-cement board is not enough, it is feared that said wood-cement board is cracked or bent by said outside environment.